The present invention relates to a retractable closure system and, more particularly, to a retractable curtain-like closure for closing the sides, ends, or top of a vehicle such as a trailer.
A variety of proposals have been made in an effort to provide a curtainside vehicle with permanently attached, movably mounted, flexible curtains that can be extended for transporting and retracted for loading of the vehicle. Curtainside vehicles provide an advantage over rigid sided vehicles in that it is possible to load curtainside vehicles from the side in a substantially obstruction-free manner. The length of the side opening of a curtainside trailer allows convenient access to the entire space of the trailer for loading with forklifts or other lifting devices.
The known curtainside vehicles generally include side walls formed of a flexible material supported along a top edge in a track. To open and close the flexible side wall curtains, a pulling or pushing force is normally applied by a human operator standing at ground level and drawing the flexible wall across the side of the vehicle. After the side wall has been positioned to cover the side opening of the trailer, the flexible wall must be fixed in place to prevent billowing of the side wall which may cause damage to the curtain or obstruct the driver's view in the vehicle side view mirrors. The securing of the flexible side walls to the vehicle body has generally been performed by attaching straps to the side wall and to a body of the trailer and tightening these straps to tension the flexible wall. However, the various known strap configurations for securing the flexible walls are rather cumbersome to assemble and tighten requiring multiple tightening steps. In addition, the straps may become twisted, tangled, or worn further complicating the securing operation.
Accordingly, it would be desirable to provide a curtainside vehicle in which the flexible curtain side wall can be automatically retracted and unfurled, and the curtain can be tensioned without needing to resort to straps.